| ▲ | buildbot 12 days ago |
| I think that might be why a lot of camera makers don't care to use DNG - it's easier to make their own format and easy enough for others to reverse engineer it. One thing that open source libraries do tend to miss is that very important extra metadata - for example, Phase One IIQ files have an embedded sensor profile or full on black frame that is not yet encoded into the raw data like it typically is for a NEF or DNG from many cameras. It does seem rawspeed handles this from a quick scan of the code. It can get more tricky - Sinar digital backs have an extra dark frame file (and flat frame!) that is not part of the RAW files, and that is not handled by any open source library to my knowledge - though I did write a basic converter myself to handle it: https://github.com/mgolub2/iatodng_rs I'm not sure how DNG would be able to handle having both a dark and flat frame without resorting to applying them to the raw data and saving only the processed (still unbayered) data. |
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| ▲ | Aaargh20318 11 days ago | parent | next [-] |
| > One thing that open source libraries do tend to miss is that very important extra metadata - for example, Phase One IIQ files have an embedded sensor profile or full on black frame that is not yet encoded into the raw data like it typically is for a NEF or DNG from many cameras. In astronomy/astrophotography the FITS format[1] is commonly used, which supports all these things and is, as the name suggests, extremely flexible. I wonder why it never caught on in regular photography. 1: https://en.wikipedia.org/wiki/FITS |
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| ▲ | buildbot 11 days ago | parent [-] | | Oh interesting! This seems like it would be a good fit ;) Especially for really old setups that had RGB color wheels and multiple exposures, exactly like a multispectral astro image might. Phase one also has a multispectral capture system for cultural heritage, which just shoots individual IIQs to my knowledge… It would work great too for multiple pixel shift shots. Possibly, the engineers just didn’t know about it when they were asked to write the firmware? It’s funny, I think most RAW formats are just weird TIFFs to some degree, so why not use this instead. | | |
| ▲ | davidkwast 11 days ago | parent | next [-] | | Yes. TIFF would "fit the bil" here. It deals with multspectral satellite images. It supports 32 and 64 bits floats and 16bits integers. | | |
| ▲ | buildbot 11 days ago | parent [-] | | Oh nice, I didn't know that TIFF could handle that as well! | | |
| ▲ | davidkwast 10 days ago | parent [-] | | TIFF is almost an multidimensional array serialization format. Obviously is centered on images but it can have many layers. Usualy RGBA but they can be have other interpretations. It supports some level of streamed writting and random access over HTTP or other ranged protocols. |
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| ▲ | 9dev 10 days ago | parent | prev [-] | | > Possibly, the engineers just didn’t know about it when they were asked to write the firmware? Considering how often I witnessed engineers trying to build something to solve a problem instead of sitting down and researching if someone else did that already, and likely better, I really wouldn’t be surprised if that is the answer to most questions in this thread. |
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| ▲ | zokier 11 days ago | parent | prev | next [-] |
| Can't you just throw such frames into additional IFDs or SubIFDs? |
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| ▲ | buildbot 11 days ago | parent [-] | | Maybe? I’m not familiar enough with DNG to say - possibly that wasn’t a thing when Phase One first started using IIQ? I doubt it was around when Sinar was - in fact the last two (esprit 65 & S30|45 ) Sinar backs do use DNG as an option! |
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| ▲ | butlike 11 days ago | parent | prev [-] |
| But can I see the difference in that applied metadata? |
